The term "calorie" was first coined in the 19th century for steam engine heat conservation. Basically, a calorie is a unit of energy required for 1 gram of water to heat 1 degree Celsius. It was in 1890 that the United States Department of Agriculture (USDA) first brought this term over to the food industry. Scientists would literally take a piece of food and light it on fire to see how much it would heat water. Some of you may remember doing this in science class, I know I do.
There is also one problem here, our bodies do not have little fires raging in our cells to produce energy, we break down macronutrients (proteins, fats, carbohydrates) to use their chemical energy. Also, instead of one enormous chemical plant, we have billions of little energy producers in our cells called mitochondria that are much more efficient. The problem that many people think and feel, is that all calories are created equal, when this simply is not the truth.
When we eat stuff, i.e. food, the chemical makeup of that stuff must be broken down into smaller stuff to be absorbed, transported and utilized by our bodies. This is not a passive process which means that we need energy to digest, or in other words, we require energy to produce energy.
The energy yielding nutrients are carbohydrates, fats and protein - also known as macronutrients (more on macronutrients in future blogs). While most foods contain all 3 macronutrients, the energy content of food depends upon the amount of these nutrients within a food as each contributes a different amount of energy.
Fat is often referred to as “energy dense” as it contributes over 2 times the amount of energy per gram than either carbohydrates or protein. Fat provides 9 kilocalories (kcal) per gram (g), while carbohydrates and protein provide 4 kcal per g. The term energy density is a measure of the energy a food provides relative to the amount of food (kcal/g).
While alcohol does contribute energy to our diets, it is not a nutrient and if taken in excess can actually impair the body’s ability to function.
Stay tuned to this blog over the following weeks as I will discuss the basics of human nutrition and elaborate on how you can structure your diet for optimal performance and body composition.
Tyler Robbins B.Sc. CSCS
Director of Fitness
Head of CrossFit